Dynamic Low Voltage Setpoint Control for Auxiliary Battery Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrified vehicles, the power drawn by the power converter for charging the low voltage auxiliary battery can exceed the power provided by the charging system, potentially discharging the high voltage battery pack, leading to a decreasing state of charge during low voltage charging.
Innovation Solution
A method and system that dynamically adjust the low voltage setpoint of the power converter to control the power draw during charging, increasing it if charge acceptance is below a threshold and decreasing it if it exceeds the available power, thereby preventing unnecessary discharge of the high voltage battery pack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power converter draws power for charging the low voltage battery, then the low voltage battery charging speed is improved, but the high voltage battery pack state of charge decreases
Solution Approach 1:
The patent implements dynamic adjustment of the low voltage setpoint during charging events. The control system continuously monitors charging conditions and adjusts the power converter's low voltage setpoint in real-time, transitioning from a static to a dynamic control approach. This allows the system to optimize charging speed while preventing excessive power draw that would discharge the high voltage battery pack.
Solution Approach 2:
The patent changes the operational parameters of the power converter by adjusting the low voltage setpoint. By modifying this key parameter dynamically based on charging conditions, the system can control the power draw from the high voltage battery pack, ensuring it remains within acceptable limits while still providing adequate charging current to the low voltage battery.
2Loss of time
If the power converter draws high power for charging the low voltage battery, then the charging time is reduced, but the power output of the charging system is exceeded
Solution Approach 1:
The patent applies partial action by adjusting the low voltage setpoint to draw only the necessary amount of power for charging the low voltage battery, rather than allowing maximum power draw. This controlled partial power extraction prevents the charging system from being overloaded while still achieving charging within acceptable timeframes.
Solution Approach 2:
The control system implements feedback by monitoring the charging conditions and the power draw of the power converter. Based on this feedback, the system dynamically adjusts the low voltage setpoint to ensure the power draw does not exceed the charging system's output capacity, while still maintaining efficient charging.
3Productivity
If the low voltage setpoint is increased to improve charging rate, then the charge acceptance threshold is exceeded, but the power converter draws more power than available
Solution Approach 1:
The patent dynamically changes the low voltage setpoint parameter based on real-time monitoring of charge acceptance and power availability. When charge acceptance is below the threshold, the setpoint is increased to improve charging rate. When power draw approaches available power output, the setpoint is decreased to prevent energy loss and system overload.
Solution Approach 2:
The control system uses feedback from charge acceptance measurements and power availability monitoring to continuously adjust the low voltage setpoint. This closed-loop control ensures the charging rate is optimized without exceeding the power converter's available power output, preventing energy loss and system stress.
Data Source
AI summary
This disclosure describes vehicle systems and methods for controlling charging of an auxiliary (i.e., low voltage) battery of an electrified vehicle. Exemplary charging methods may dynamically adjust a low voltage setpoint of a power converter during the low voltage support. The proposed systems and methods therefore achieve constrained low voltage support by controlling the power drawn by the power converter at an appropriate level during the low voltage support.